JP4746022B2 - Multilayer composite and method for producing the same - Google Patents

Abstract

The invention provides a multilayer composite which comprises at least two composites. Each composite comprises a film made of a dielectric material and having a front surface and rear surface. The front surface comprises a surface pattern of raised and depressed surface portions. Furthermore, each composite comprises a first electrically conductive layer being deposited onto the surface pattern. The electrically conductive layer has a corrugated shape which is formed by the surface pattern of the film. The multilayer composite can be utilised for conversion between electrical and mechanical energies and can therefore be used as a transducer.

Description

  The present invention relates to a multilayer composite having conductive layers and dielectric material layers interleaved with each other. This multi-layer composite can be used to convert between electrical energy and mechanical energy, and therefore can be used as a sensor, actuator, generator or transformer, and these four structures are referred to as transducers below. To.

  The potential difference between the two electrodes located on both sides of the elastomeric body generates an electric field that leads to an attractive force. As a result, the distance between the electrodes changes, and this change leads to compression of the elastomeric material that is deformed thereby. Due to some similarities with muscles, elastomeric actuators are sometimes called artificial muscles.

  U.S. Pat. No. 6,376,971 is placed against a polymer and the electric field generated between the electrodes when a constant potential difference is applied between the electrodes causes the electrodes to contract each other, thereby A flexible electrode to deflect is disclosed. Since the electrodes are made of a substantially rigid material, the electrodes must be textured to make them flexible.

  The electrodes are described as having “in-plane” or “out-of-plane” flexibility. In US Pat. No. 6,376,971, an out-of-plane flexible electrode is disposed by stretching the polymer beyond the amount that would normally be stretchable during actuation, and a rigid material layer is disposed on the stretched polymer surface. accumulate. For example, the rigid material can be a polymer that cures while pulling the electric field responsive polymer. After curing, the electric field responsive polymer relaxes and the structure exhibits a textured surface. The thickness of the rigid material can be varied to provide any size texture including levels below μm. Otherwise, textured surfaces can be generated by reactive ion etching (RIE). As an example, RIE is applied to a prestrained polymer made of silicon with RIE gas consisting of 90% carbon tetrafluoride and 10% oxygen to form a wave-like surface with a depth of 4-5 μm. can do. As another alternative, the electrode can be attached to the surface of the polymer. The electrode attached to the polymer preferably conforms to the deformed shape of the polymer. Textured electrodes can be flexible in multiple directions. An electrode having a rough texture can be flexible in the orthogonal plane direction.

  U.S. Pat. No. 6,376,971 discloses a planar flexible electrode to be structured and a unidirectionally flexible device, wherein the metal wiring path is a parallel line on the charge distribution layer. Both lines cover the active area of the polymer. Metal wiring paths and charge distribution layers are applied to both sides of the polymer. The charge distribution layer promotes the charge distribution between the metal wiring paths and has flexibility. As a result, the structured electrode allows deflection in a flexible direction perpendicular to the parallel metal wiring path. In general, the charge distribution layer has a conductivity higher than that of the electric field responsive polymer, but it is smaller than the metal wiring path.

  The polymer can be pre-strained in one or more directions. Pre-strain is obtained by mechanically stretching the polymer in one or more directions and securing it to one or more solid members (eg, a rigid plate) while being distorted. Another technique for maintaining pre-strain includes the use of one or more stiffeners. Stiffeners are long rigid structures that are placed against a polymer while in a pre-strained state, for example, while stretched. The stiffeners maintain prestrain along their axes. Stiffeners can be placed in parallel or according to other structures to achieve directional flexibility of the transducer.

  The flexible electrode disclosed in US Pat. No. 6,376,971 is provided with conductive grease such as carbon grease or silver grease which provides flexibility in multiple directions, or this electrode is made of carbon fibril or carbon. It can be composed of a mixture of nanotubes or ion conductive materials or a colloidal suspension. The colloidal suspension includes particles having a size of less than μm such as carbon fiber, silver, and gold in a liquid medium.

  The polymer can be a commercial product such as a commercially available acrylic elastomer thin film. It can be a thin film produced by casting, dipping, spin coating or spraying.

  Textured electrodes known in the prior art can alternatively be patterned by lithography. In this case, a photoresist is deposited on the pre-strained polymer and patterned using a mask. Plasma etching can remove portions of the field responsive polymer that are not protected by the mask in the desired direction. The mask can be substantially removed by appropriate wet etching. The working surface of the polymer can then be coated with a thin layer of gold deposited, for example by sputtering.

  It is the corrugated electrode that produces electric field responsive polymers, particularly wound actuators, using the techniques described in US Pat. No. 6,376,971 and US Pat. No. 6,891,317. It has the disadvantage that it is very difficult to control the direction of flexibility.

  Finally, in order to obtain the necessary flexibility using the prior art, it is necessary to use a material with a relatively high electrical resistance for the electrodes. Since a winding actuator having a large number of windings will implicitly have very long electrodes, the total electrical resistance for the electrodes will be very high. The response time for this type of actuator is given by τ = R · C, where R is the total electrical resistance of the electrode and C is the capacitance of the composite. Thus, a high overall electrical resistance results in a very long response time for the actuator. Thus, in order to obtain an acceptable response time, the number of turns must be limited, thereby also limiting the driving force, i.e. the response time and the driving force must be harmonized when designing the actuator.

US Pat. No. 6,376,971 US Pat. No. 6,891,317

  One object of a preferred embodiment of the present invention is to provide a dielectric structure that facilitates an increased conversion ratio between electrical and mechanical energy compared to prior art dielectric structures.

According to a first aspect of the present invention, the above and other objects are realized by a multilayer composite comprising at least two composites, each composite comprising:
It is made of a dielectric material, has a front surface and a back surface, and the front surface includes a surface pattern including a raised surface portion and a recessed surface portion,
A first conductive layer deposited on the surface pattern, the conductive layer having a corrugated shape formed by the surface pattern of the thin film.

  The multilayer composite provides several advantages over known dielectric structures. The lamination of some composites is not only due to the synergistic effect of each layer, but also due to the fact that the multilayer structure itself makes this multilayer composite more robust than the corresponding “one layer device” with the same physical dimensions. Resulting in increased exchange between energy and electrical energy. In addition, the multilayer structure facilitates the application of an electric field to the thinner part of the structure, thereby requiring much less potential across the electrodes than using a corresponding “one-layer device” having the same physical dimensions. .

  The invention of a multilayer structure of corrugated electric field response composites also facilitates the construction of more powerful transducers than prior art transducers. This is true because the invention of an efficient electric field responsive composition laminate in an unlimited number of layers provides an unlimited cross-sectional area and allows for a very powerful transducer.

  Lamination of the composite also provides a simple and efficient way of placing the conductive layers on both sides of the thin film, because one thin film conductive layer becomes the adjacent thin film of the adjacent composite. In a multilayer composite having 10 composites, 9 composites are of electric field responsive type, i.e. they have conductive layers on both sides, which can be deformed by applying a potential difference between the conductive layers.

  The invention of multi-layer structures with metal electrodes having low sheet resistance also results in small response times when using multi-layer composites in transducers.

  The dielectric material may be any material such as a material having a relative dielectric constant εr of 2 or more that can support an electric field without being energized. It can be a polymer, e.g. an elastomer such as a silicone elastomer, e.g. a weakly adherent silicon or a material that generally has elastomer-like characteristics with respect to elastic deformation. For example, Elastosil RT 625, Elastosil RT 622 and Elastosil RT 611, all from Wacker-Chemie, can be used as the dielectric material.

  It should be noted that when using a dielectric material that is not an elastomer, the dielectric material should have elastomer-like properties, for example, in terms of elasticity. That is, the dielectric material must be deformable to the extent that the multilayer composite can be pulled and / or pushed due to deformation of the dielectric material.

  The conductive layer can be composed of silver, gold, nickel, or a conductive alloy.

  Multi-layer composites are created by placing composite layers in a stacked state, applying a predetermined potential difference between each adjacent conductive layer in the stack, thereby urging the layers toward the other and simultaneously flattening them. can do. Due to the physical properties of the thin film, the above method can combine the layers. Otherwise, or in addition, the layers can be bonded by an adhesive placed between each layer. This adhesive should preferably be selected so as not to inhibit the flexibility of the multilayer structure. Therefore, it is preferable to select the same material for the thin film and the adhesive, or to select an adhesive having an elastic modulus lower than that of the thin film.

  In order to be able to stretch the composite in one well-defined direction, i.e. to provide flexibility, the conductive layer has a length of the conductive layer in the lengthwise direction of this type of composite. A corrugated shape that is longer than the length in the direction is provided. The corrugated shape of the conductive layer facilitates the composite to be elongated in the length direction by simply equalizing the corrugated shape of the conductive layer, thereby not forcing the conductive layer to stretch in that direction. According to the present invention, the corrugated shape of the conductive layer is a replica of the surface pattern of the thin film.

  Since the conductive layer is deposited on the surface pattern of the thin film and formed according to its shape, it is possible to form a very precise corrugated shape of the conductive layer, and in a specific direction deformation by appropriate design of the surface pattern on the thin film Improved flexibility can be provided. Thus, the composite has an increased driving force, generally increased conversion efficiency between mechanical and electrical energy, increased lifetime, and improved reaction time when the composite is used in a transducer. Can help.

  In prior art composites, the thin film and electrode pattern is formed by stretching the thin film prior to application of the electrode to the thin film surface. When the extension of the membrane is released, the electrode contracts and the membrane surface contracts with the electrode because the electrode is bonded to the membrane. Since the shape of the conductive layer according to the present invention is a replica of the shape of the surface pattern of the thin film, the shape of this kind of composite can be formed so as not to be affected by contact or bonding between the conductive layer and the thin film. Furthermore, the shape can be made substantially unaffected by the elastic modulus of the conductive layer and the thin film. Furthermore, it can be prevented from being affected by the thickness of the conductive layer and the thin film. This provides greater freedom in material selection for the thin film and conductive layer, thus allowing improved performance of the composite when used in a transducer.

  In order to suppress deformation of the composite body in a direction other than the flexible direction, the conductive layer can have an elastic coefficient that greatly exceeds the elastic coefficient of the thin film. Thus, the conductive layer resists stretching, thus preventing deformation of the composite in a direction where the length of the conductive layer corresponds to the length of this type of composite.

  The composite layers within the multilayer composite should preferably be the same, ensuring homogenous deformation of the multilayer composite throughout all of the layers when an electric field is applied. Furthermore, the corrugation pattern of each layer should be applied in such a manner that a wave peak of one layer is adjacent to a wave peak of an adjacent layer, or a mountain of one layer is adjacent to a valley of an adjacent layer. Would be convenient.

  It may be advantageous to place the composites opposite each other on the back. Thus, the multilayer composite is less vulnerable to defects in the thin film. If a thin film in one layer has a defect that allows the electrodes on both sides to be short-circuited, it is very unlikely that the layer on the back of the film in question has a defect in the same location. . In other words, at least one of the two thin films provides electrical insulation of the two conductive layers. This multi-layer structure can be expanded with further composites, whereby the composites are made into a pair of back bond laminates or front bond laminates. In this structure, two adjacent thin films in contact with each other reduce the influence of defects in each thin film, and two adjacent conductive layers in contact with each other reduce the influence of defects in each conductive layer.

  As an alternative, the composites can be arranged such that the front side of one composite faces the back side of an adjacent composite.

  A particular advantage of multi-layer composites is to obtain a cross-sectional second moment that bends the multi-layer composite whose properties of the laminated structure are at least 1.5 to 3 times, for example twice, the average cross-sectional second moment of each composite. It can be used to make a multilayer composite that is much more rigid than each composite in a sufficient number of composites.

  This composite can be made of a material, for example a thin film made of a polymeric material having adhesion properties. When the composites are laminated, the adhesion properties of the thin film can be bonded to each other somewhat weaker than, for example, promoting delamination without damaging each composite. To increase the stiffness of the multilayer composite, the composites can be tightly bonded to each other through the use of additional adhesives. In one embodiment, they are bonded to some extent that they cannot be delaminated without destroying the composite. If an additional adhesive is used, the adhesive can have elastic properties similar to a thin film. The adhesive may comprise or be made of the same material that constitutes at least the main part of the thin film, for example. In particular, the adhesive can have a hardness that is at most as high as that of the thin film of the composite.

  The surface pattern and corrugation of the composite should preferably be substantially equal so that each layer within the multilayer composite has the same expansion properties, i.e., each layer can be expanded equally to the applied electric field across the thin film. However, in some cases it may be desirable to establish different expansion properties of the layers, for example by different corrugations of the conductive layers of each composite.

  The thin film and the conductive layer can have a relatively uniform thickness, for example, a maximum thickness of less than 110% of the average thickness of the thin film and a minimum thickness of at least 90% of the average thickness of the thin film. Accordingly, the first conductive layer has a maximum thickness that is less than 110% of the average thickness of the first conductive layer and a minimum thickness that is at least 90% of the average thickness of the first conductive layer. be able to. From an absolute point of view, the conductive layer can have a thickness in the range of 0.01 μm to 0.1 μm, for example in the range of 0.02 μm to 0.09 μm, for example in the range of 0.05 μm to 0.07 μm. . That is, the conductive layer is preferably applied to the thin film as an ultrathin layer. This facilitates good performance and helps the conductive layer follow the corrugated pattern on the surface of the thin film.

  The conductive layer can have a thickness in the range of 0.01 to 0.1 μm, and this thin film can be between 10 μm and 200 μm, such as between 20 μm and 150 μm, such as between 30 μm and 100 μm, such as between 40 μm and 80 μm. Can have a thickness of between. In this context, the thickness of the thin film is defined as the shortest distance between a point on one face of the thin film and an intermediate point located midway between the peaks and valleys of the corrugated face of the thin film.

Conductive layer has a resistance of less than 10 ^-4 Ω · cm for each 10 ^-4 Ω · cm less than or complex.

  By providing a conductive layer having a very low resistance, the total resistance of the conductive layer does not become excessive even if a very long conductive layer is used. Thereby, the response time required to convert between mechanical energy and electrical energy can be kept at an acceptable level, while allowing a large surface area for the composite, thereby driving a large drive when the composite is used in an actuator. You can gain power. In the prior art, it is impossible to provide a corrugated conductive layer having a sufficiently low electric resistance. The main reason is that the prior art is based on appropriate examination of materials having other characteristics in order to provide flexibility. This is because it is necessary to select a material related to the conductive layer. According to the present invention, it is thus possible to provide a flexible conductive layer with a material having a very low resistance, since this makes it possible to obtain a large driving force, whilst an acceptable response time of the transducer. It is because it is kept.

  The conductive layer can be made of a metal or a conductive alloy, preferably a metal selected from the group consisting of silver, gold and nickel. Otherwise, other suitable metals or conductive alloys can be selected. Since metals and conductive alloys usually have very low resistance, the aforementioned advantages can be obtained by making the conductive layer from a metal or conductive alloy.

The dielectric material has a resistivity greater than ¹⁰ 10 Ω · cm each or complex exceeds ¹⁰ 10 Ω · cm.

Preferably, the resistance of the dielectric material is much greater than the resistance of the conductive layer, preferably at least 10 ¹⁰ to 10 ¹⁸ times greater.

  The waveform pattern includes waves forming peaks and valleys extending in one common direction, and waves having anisotropy characteristics promote movement in a direction perpendicular to the common direction. According to this embodiment, the wave peaks and valleys are similar to standing waves with substantially parallel wave fronts. However, this wave is not necessarily a sine wave and can have any suitable shape as long as peaks and valleys are identified. According to one embodiment, the peaks (or valleys) will form a substantially straight contour, i.e., a line along a portion of the corrugation having a height approximately equal for each complex. The at least substantially straight line is at least substantially parallel to a similar contour line formed by other peaks or valleys, and the direction of at least the substantially straight line determines a common direction. The common direction thus determined has the result of anisotropy, and the movement of the composite in the direction perpendicular to the common direction is facilitated, i.e. the composite or at least the conductive layer arranged on the corrugated surface is common. Flexibility in the direction perpendicular to the direction. In connection with a potentially unlimited web, wave peaks and valleys can extend, for example, lengthwise or laterally.

  Preferably, the flexibility of the composite in the flexible direction is at least 50 times greater than its flexibility in the common direction, ie perpendicular to the flexible direction.

  The wave can have a periodically repeating shape. In one embodiment, this means that each mountain and each valley is at least substantially identical. Otherwise, this periodicity can be obtained with larger dimensions, i.e. the repeating pattern can be several "wavelengths" long. For example, the wavelength, the amplitude of the peak / valley shape, etc. can be repeated periodically. As an alternative, the wave shape can be aperiodic.

  Each wave can have a height that is the shortest distance between the mountain and the adjacent valley. In this case, each wave can be determined with a maximum wave having a height of at most 110% of the average peak value and / or each wave has a minimum wave with a height of at least 90% of the average peak value. You can also decide. According to this embodiment, the variation in wave height is very small, that is, a very uniform pattern is obtained.

  According to one embodiment, the average peak value of the waves can be between 1/3 μm and 20 μm, such as between 1 μm and 15 μm, such as between 2 μm and 10 μm, such as between 4 μm and 8 μm.

  Otherwise, or additionally, this wave can also be specified as the shortest distance between two peaks, and the ratio between the average peak value of the wave and the average wavelength is, for example, 1 / 30-2, for example 1 / It can be set to 20 to 3/2, for example, 1/10 to 1.

  This wave can have an average wavelength in the range of 1 μm to 20 μm, for example in the range of 2 μm to 15 μm, for example in the range of 5 μm to 10 μm.

  The ratio between the average height of the wave and the average thickness of the thin film is between 1/50 and 1/2, such as between 1/40 and 1/3, such as between 1/30 and 1/4, such as 1 / 20 to 1/5.

  The ratio between the average thickness of the conductive layer and the average wave height is between 1/1000 and 1/50, for example between 1/800 and 1/100, for example between 1/700 and 1/50. be able to.

  In a preferred embodiment of the present invention, the composite is described above in such a way that not only the properties of the conductive layer material but also the dielectric and mechanical properties of the thin film are taken into account and a composite having the desired properties is obtained. Design with optimized parameters. Thus, the average thickness of the thin film can be selected with reasonable consideration for the relative dielectric constant and breakdown electric field on the one hand and for the potential difference between the conductive layers on the other hand. Similarly, the height of the peaks can be optimized for the thickness of the thin film to obtain a relatively uniform electric field distribution across the thin film of dielectric material disposed between the conductive layers. Furthermore, the thickness, average wavelength, and peak value of the conductive layer can be optimized so as to obtain desired flexibility. This will be further described below with reference to the drawings.

  The multilayer composite may be provided with a peripheral edge coated with an electrically insulating layer to prevent, for example, a short circuit between conductive layers of the multilayer composite or to generally protect the edges of the multilayer composite.

  For example, in a transducer comprising a multi-layer composite that is wound or wound to form a winding structure having a number of layers or windings, the multi-layer composite is extremely It is preferably provided as a long web. In this context, the web represents potentially something that can be offered as a spooled product that is similar in length, and thus resembles an adhesive wrap, adhesive film or household foil. In general, the web is at least 10 times longer in the length direction than in the vertical transverse direction, but it can be 100 times or 1000 times or even longer in the length direction. The corrugation can extend in any direction relative to the length and transverse directions. However, it is preferred to extend the corrugations of all composites that make up the multilayer composite in the same direction.

  To form a transducer from a multi-layer composite, the multi-layer composite includes an actuator that can act on the surrounding environment, such as pressure, on an adjacent object, a sensor or transducer that can detect pressure, It must be shaped and rigid enough to interact with the generator.

  In providing shape and structure, a multi-layer composite, for example, pre-strains in at least one direction, for example by stretching the multi-layer composite in a rigid frame, i.e. a frame that is rigid relative to the multi-layer composite. can do. In particular, it may be preferred to extend the multilayer composite perpendicular to its flexible direction, ie the direction in which the wave peaks and valleys extend. To elongate the multi-layer composite, an elastic element, such as a spring or similar elastic deformable element, may be placed between the rigid frame and the multi-layer composite. A multilayer composite is placed, for example, on a movable rigid beam or another multilayer composite so that the composite remains pre-stretched and the deformation of the multilayer composite is measured on two conductive layers. It can also be detected as a change in capacitance, or an electric field can deform the thin film, thus elongating the elongated multilayer composite.

  Another way to provide shape and structure is to fold, roll or otherwise stiffen the multilayer composite. This provides sufficient rigidity to the multilayer composite and allows the use of the multilayer composite as an actuator that can push and pull by exerting forces on adjacent objects.

  Multi-layer composites can be used as transducers that drive, detect and control components such as valves, flaps, pumps, and dosing pumps. This type of control component can be applied to industrial, household and defense applications such as hydraulics, industrial automation and control, heating and refrigeration, ventilation and air conditioning, maritime, medical, automotive and off-road equipment.

  The capacity of such a multilayer composite varies as a function of the deflection of the composite. When the multilayer composite is used in combination with an electronic control circuit, the capacitance change can be converted into a control signal to indicate deflection of the transducer. This type of control signal can be used as an input to improve closed loop (feedback) control, such as transducer position.

  The multilayer composite used in combination with the control electronics for transducer positioning can be applied to the application for precisely responsive control of the components.

  In one specific embodiment, the multilayer composite is made from a single continuous film made of a dielectric material. The thin film is provided with a front surface having a surface pattern composed of a raised surface portion and a recessed surface portion. For example, a first conductive layer having a corrugated shape is deposited on the first portion of the surface pattern, and a second conductive layer having a corrugated shape is deposited on the second portion of the surface pattern, for example. The first and second conductive layers are electrically insulated from each other by, for example, providing a line or strip on which no conductive material is deposited on the thin film. Thus, the thin film is folded or wound, or otherwise formed into a multilayer composite structure in which the first and second conductive layers are alternately disposed between the thin film layers. In other words, winding or folding of this “single continuous thin film” version of the multilayer composite is done to both provide rigidity and interposition of the two conductive layers. When folding a “single continuous thin film”, the thin film is protected in a manner that prevents the electrodes from being short-circuited, while ensuring that the electrodes of opposite polarity are placed opposite each other with the dielectric thin film layer interposed therebetween. Note that care must be taken to fold the.

In forming the transducer, electrical connectivity between the conductive layer and the electronic circuit or power supply is required. The “single continuous thin film” described above can have only two conductive layers, since it is a single layer that is folded or wound. However, other types of multilayer composites comprise a plurality of individual conductive layers, one for each composite within the multilayer composite. In this case, the connection between each second conductive layer and one connector of the electronic circuit or power supply and the connection between each intermediate conductive layer and another connector of the electronic circuit or power supply are arranged in a multilayer composite. In which the conductive layers are transitioned to each other for each second layer. As an example, the composite thin film forms a dielectric layer having a first surface and a second surface opposite the conductive layer. The conductive layer is
An active portion of the actuator, wherein the active portion has both sides of the dielectric layer covered with electrode portions of the conductive layer;
The first passive portion and the second passive portion can be defined by covering only one surface of the dielectric layer with one of the conductive layers.
The first passive portion is formed by the contact portion of the conductive layer on the first surface, and the second passive portion is formed by the contact portion of the conductive layer on the second surface.

  An electrical connector can then be attached to each contact to connect the contact to a power source or electronic circuit. As an example, conductive rods, bolts, nails, screws, rivets are inserted through all the layers of the multilayer composite through each contact point, thus electrically connecting the multilayer composite to a power supply or electronic circuit. Can be used.

In a second aspect, the present invention provides a method for supplying a multilayer composite comprising a dielectric thin film and a conductive layer. This method
Providing the first composite comprising a thin film comprising a dielectric material having a back surface opposite the front surface, wherein the front surface comprises a surface pattern comprising a raised surface portion and a recessed surface portion;
Depositing a conductive layer on the surface pattern;
Providing a second composite having a back surface opposite the front surface, wherein the front surface comprises a surface pattern comprising a raised surface portion and a recessed surface portion;
Depositing a conductive layer covering at least a portion of the surface pattern;
Disposing the first complex on the second complex;
Fixing the position of the first complex with respect to the second complex.

  The final step of fixing the position can be done by using the adhesion properties of the thin film itself or by using an additional adhesive applied between the composites. Otherwise, the layers can be secured to a common securing means, for example by attaching all the layers to a common frame or flange or similar component that can hold the layers together.

  Preferably, the multi-layer composite is made as a spooled product that is potentially unlimited in length. In accordance with this purpose, the step of arranging the composite and the step of arranging them in the laminate can also be carried out in a continuous manner, in which a part of the multilayer composite is created while the multilayer composite is Finish another part and wind it up.

  For example, the composite is provided with a shape specifying element having a surface pattern made up of a raised surface portion and a recessed surface portion, and a surface having a replication pattern made up of the raised surface portion and the recessed surface portion by supplying a liquid polymer composition onto the surface pattern. Provided by forming a first thin film having: This can be done, for example, by coating, molding, painting, spraying, or any other manufacturing method that can bring the liquid polymer onto the surface in a predetermined surface pattern. Because the same layer is provided in the multilayer composite, the same or exactly the same shape-identifying element can be used throughout the process.

  The conductive layer can be deposited on the replica surface pattern using a physical vapor deposition method such as sputtering or electron beam. The conductive layer is deposited on the thin film with a thickness of 0.01 to 0.1 μm, and the thickness is controlled by a quartz crystal microbalance.

  A quartz crystal microbalance is a thickness measurement technique commonly used for physical vapor deposition. It allows the thickness of the vapor deposited coating, such as a metal coating or similar coating, to be controlled with accuracy in the sub-nanometer range.

  Prior to application of the conductive layer, the thin film can be treated with plasma because this improves the adhesion of the conductive layer to the thin film. The plasma treatment can be performed using glow discharge, which is known to generate low stimulation plasma, and argon plasma is preferred.

  Plasma cleaning is an indispensable step in metal coating processing of elastomeric thin films. It increases the adhesion of the deposited material. However, not all plasmas are suitable for processing elastomeric thin films, and the plasma must therefore be selected carefully. As mentioned above, argon plasma is preferred. Plasma treatment is known to form a thin and extremely robust silicate “glassy” layer at the elastomeric boundary. Subsequent application of the conductive layer results in a corrugated electrode with limited flexibility and a composite that cannot be stretched very greatly due to the risk of cracking the robust electrode. Argon plasma treatment is selected here, but this treatment is not reactive because argon is a rare gas. However, oxygen and other reactive gases remaining in the vacuum deposition chamber combined with argon plasma can cause a slight reaction. Not only the process duration, but also the argon pressure in the vacuum chamber and the low-stimulus glow discharge parameters are optimized to adhere the deposited metal coating to the elastomer film very well. The resulting corrugated electrode is very flexible, and the composite can be stretched as much as possible without damaging the electrode according to the design criteria described in the previous paragraph.

  After the plasma treatment, an adhesion promoter can be applied to the thin film. The adhesion promoter can be composed of a chromium layer or a titanium layer, and the adhesion promoter can be applied to the thin film by physical vapor deposition.

  In an alternative method, the liquid polymer composition is disposed directly on the first film or conductive layer by direct molding or coating onto the first film and the second film is disposed. The replicate pattern can in this case be arranged by embossing simultaneously into the uncured or partially cured polymer using an embossing tool. When the polymer is cured, at least a portion of the pattern can be coated with the second conductive layer. This process can be repeated to provide a multilayer composite comprising multiple layers.

Best Mode for Carrying Out the Invention

  The present invention will now be described in more detail with reference to the accompanying drawings.

  1a and 1b show a continuous roll of a composite 1 with a spool according to an embodiment of the present invention, and FIG. 1c is a perspective view of a part of the composite 1. FIG. The balance of the composite is distorted in illustrating the different elements of the composite 1. The composite 1 comprises a thin film 2 made of a dielectric material having a surface 3 with a pattern consisting of a raised surface portion and a recessed surface portion and forming a design waveform contour of the surface 3. A conductive layer 4 is applied to the surface 3, and a conductive material is deposited so that the conductive layer is formed according to a pattern consisting of a raised surface portion and a recessed surface portion. In the case of tangible daily necessities, the thin film 2 is similar in part to a household packaging film. It has a similar thickness and is relatively bendable and soft. However, it is more elastic than this type of film and has significant mechanical anisotropy that will be described below.

  The dielectric material can be an elastomer or another material having similar properties.

  Due to the pattern of the raised surface portion and the recessed surface portion, the conductive layer 4 is made uniform when the thin film 2 extends, and causes damage to the conductive layer 4 when the thin film 2 contracts along the direction indicated by the arrow 5. Rather, it restores its original shape and this direction thereby defines the direction of flexibility. Accordingly, the composite 1 forms part of a flexible structure that can withstand large strains.

  As described above, the corrugated surface contour is stamped or molded directly into the dielectric thin film 2 before the conductive layer is deposited. The waveform enables the production of a flexible composite using an electrode material having a high elastic modulus, for example, a metal electrode. This can be obtained without applying pre-elongation or pre-strain to the dielectric thin film 2 while applying the conductive layer 4, and the waveform contour of the completed composite 1 depends on the strain of the dielectric thin film 2. It does not depend on the elasticity or other characteristics of the conductive layer 4. Accordingly, the waveform contour is replicated over substantially the entire surface 3 of the dielectric thin film 2 in a consistent manner, and this replication can be controlled. In addition, this approach offers the possibility of using standard replication and reel-to-reel coating, which makes the process suitable for mass production. For example, the conductive layer 4 can be applied to the surface 3 of the dielectric thin film 2 using standard commercial physical vapor deposition (PVD) techniques. The advantage of this approach is that the anisotropy is determined by the design, and the actual anisotropy is obtained as a result of the waveform contour disposed on the surface 3 of the dielectric thin film 2 and the characteristics of the conductive layer 4 following the waveform contour. It is done.

  The composite 1 shown in FIG. 1c has a flexibility within the range of flexibility of the dielectric thin film 2 in the direction defined by the arrow 5 and a stiffness within the range of the stiffness of the conductive layer 4 in the direction defined by the arrow 6. Designed to have In FIG. 1, the flexible direction runs along the length of the composite 1, whereas the flexible direction in FIG. 1 b crosses the composite 1. This is shown along the composite 1 in FIG. 1b by a thin line across the composite 1 in FIG. 1a, which represents a pattern of raised and recessed surface portions forming a wavy contour. The composite 1 can be produced in a so-called “endless” composite that can be stored as a very long length spool as shown in FIGS. 1a and 1b. This type of semi-finished product can be used in the manufacture of transducers, such as actuators.

  2a to 2f show a part of a cross-sectional view of the composite 1 according to an embodiment of the present invention in which shading is omitted for the sake of clarity. Each part only represents half of the composite 1 as indicated by the symmetry line 10 at the bottom of each part. Furthermore, the conductive layer 4 can be deposited on the lower surface of the dielectric thin film 2, which also forms a corrugated surface, thereby creating an electric field responsive complex, ie at least two conductive layers separated by the dielectric thin film. Can be formed. Furthermore, each part only shows a small part of the length of each complex. For the purposes of illustration, the ratio of FIGS. 2a-2g is not constant. FIG. 2g is an enlarged cross-sectional view of FIGS. 2a, 2b, 2c, 2d, 2e, 2f. The complex 1 shown in FIGS. 2a to 2g is, for example, the complex of FIG. 1a. That is, the composite 1 includes a thin film 2 made of a dielectric material having a surface 3 having a pattern composed of a raised surface portion and a recessed surface portion, thereby forming a wavy contour of the surface 3. Surface 3 comprises a conductive layer (shown in FIG. 2g) that forms the directional flexible composite described above. As shown in FIGS. 2a to 2f, the pattern including the raised surface portion and the recessed surface portion can be designed with various shapes.

  The waveform contour can be represented by a series of good periodic sinusoidal three-dimensional microstructures. Otherwise, the waveform contour can have a triangular contour or a square contour. The mechanical deflection coefficient Q of the corrugated electrode is determined by the dimension ratio between the corrugation depth d and the thickness h of the conductive layer 4 (see FIG. 2g), and the dimension between the corrugation depth d and its period P. It depends on the ratio. The most dominant factor is the dimensional ratio between the waveform height d and the thickness h of the conductive layer 4. The greater the deflection factor, the more flexible the structure. Assuming perfect flexibility, the dimensional ratio between the waveform depth d and its period P is theoretically about 32% for the curved contour and about 28% for the triangular contour compared to the original length. The square contour can also be extended by about 80%. In practice, however, this is not the case, because the square contour comprises a vertical beam and a horizontal beam, which gives different flexibility, because the vertical beam bends and thereby adapts very much to the direction of displacement. Movement is born while horizontal beams are much more rigid because they extend in the direction of displacement. Therefore, it is often desirable to select a curved contour.

  In the composite 1 shown in FIGS. 2a to 2f, the waveform pattern pressed or formed in the dielectric thin film 2 can be represented by a series of well-formed periodic sinusoidal three-dimensional microstructures. The waveform contour is formed on the upper surface 3 of the thin film 2 as shown in FIGS. 2a to 2f. A second wavy contour is formed on the lower surface (not shown) of the thin film as indicated by the symmetry line 10. 2a-2f, the cross section runs along the direction of flexibility. Straight lines perpendicular to the flexible direction represent the top and bottom of the raised and recessed surface portions, that is, the crests and valleys of the sinusoidal microstructure. This can be seen more clearly in FIGS. 1a and 1c. The flexibility along these parallel straight lines is very low, i.e. the composite 1 is not flexible in this direction for all practical purposes. In other words, this design represents a one-dimensional wave, which transforms the dielectric thin film 2 into an electric field responsive composite 1 with anisotropic flexibility upon application of the conductive layer, where the thin film is free The cross-sectional direction arranged in the vertical direction, while contracting or stretching, is “frozen” due to the built-in boundary conditions brought about by the mechanical resistance of the conductive layer 4.

  2a-2g, d represents the average or typical corrugation depth, i.e., the average or typical distance between the raised portion of the pattern and the adjacent recess. H represents the average thickness of the dielectric thin film 2, and h represents the average thickness of the dielectric layer 4. In a preferred embodiment, the average thickness H of the dielectric thin film 2 is in the range of 10 μm to 100 μm. 2a-2c show a composite 1 having different corrugation depths d, but the waveform period P is substantially the same for the three composites shown. Comparing the complex 1 of FIG. 2d and FIG. 2e, the waveform depth d is substantially the same, but the waveform period P of the complex 1 of FIG. 2e is greater than the waveform period P of the complex 1 shown in FIG. It ’s big. Compared here, the composite 1 of FIG. 2f has a smaller waveform depth d and a larger waveform period P.

  The characteristics of the dielectric thin film 2 having the anisotropic corrugated flexible metal electrode in the form of the conductive layer 4 described according to the present invention are optimized by the design according to the design criteria developed by the inventor. These design criteria take into account the dielectric and mechanical properties of the dielectric material and the conductive layer material.

  On the other hand, the relative dielectric constant and breakdown electric field of the dielectric material, and on the other hand, the potential difference between the electrodes are design parameters that determine the range of the average thickness H of the dielectric thin film 2. The characteristic properties of dielectric materials are usually provided by dielectric manufacturers such as Wacker-Chemie and Dow Corning.

  The waveform depth d is optimized with respect to the dielectric thin film thickness H in order to obtain a relatively uniform electric field distribution of the entire dielectric thin film positioned between the electrodes. This kind of optimization process is performed using a finite element simulation method. A high d / H ratio corresponds to a non-uniform electric field distribution, and a low d / H ratio corresponds to a relatively uniform electric field distribution.

  The anisotropic and flexible properties are the combined result of the shape and geometric structure imparted to the surface of a dielectric thin film, such as an elastomer thin film, on the one hand by the molding process and on the other hand by the conductive layer that captures the corrugated shape. The electrode layer thickness h and the corrugation period P are determined by corrugation depth to obtain a dielectric thin film having a metal electrode that is flexible in the “in-plane” direction and hardly flexible in the transverse “in-plane” direction. Optimize for d. A film that is very flexible in one direction can be stretched or stretched significantly in this direction by applying a relatively low level of force in this direction without the risk of damaging the electrodes. A thin film having a very limited elongation in the transverse direction when a force is applied in the transverse direction. In order to optimize the flexibility of the electrodes, the d / P ratio and the h / d ratio must be optimized. A high d / P ratio results in a much more flexible electrode, and a low d / P ratio results in a less flexible electrode. A high h / d ratio results in a less flexible electrode, and a low d / P ratio results in a much more flexible electrode. The degree of anisotropy of the dielectric thin film with corrugated electrodes is determined by the flexibility ratio between the direction in which the composite is bent and the transverse direction in which the composite is hardly bent. A high flexibility ratio results in a more anisotropic structure, and a lower ratio results in a more isotropic structure.

  Once the range for the design parameters (H, d, h, P) has been specified according to the above description, what is the degree of flexibility and the maximum extension in the direction of flexibility it can receive and the driving force? In that respect, it is possible to predict the performance of a dielectric with a metal electrode in the form of a conductive layer. Transverse stiffness can also be predicted. The purification process regarding these parameters can be performed as necessary.

  For a given driving force, an actuator made from a dielectric material manufactured according to the present invention, i.e. having electrodes deposited thereon, has a much smaller weight, i.e. a magnetic actuator capable of supplying a considerable driving force, etc. Note that it has a weight that is at least one-fifth lower than conventional actuators. This is very important for applications where the volume and weight of the actuator are related.

  Once all design parameters are optimized, the mold is designed according to strict specifications for the corrugated geometry.

  Based on the finite element method electrostatic simulation, the inventors of the present invention have found that the ratio d / H should be in the range of 1/30 to 1/2. For example, by giving a ratio of 1/5 and a waveform depth of about 4 μm, the thickness of the dielectric thin film 2 becomes approximately 20 μm. Furthermore, the ratio d / P between the corrugation depth d and the corrugation period P and the ratio h / d between the thickness h of the conductive layer and the corrugation depth d directly affect the flexibility of the electrode. An important ratio. In a preferred embodiment, the ratio d / P is in the range of 1/50 to 2 and the ratio h / d is in the range of 1/1000 to 1/50.

  Another problem to consider when determining the average thickness H of the dielectric thin film 2 is the so-called breakdown electric field associated with the dielectric material. When a conductive layer 4 is deposited on each side of the dielectric thin film 2, thereby forming an electric field responsive composite, the voltage V between these conductive layers for a given material thickness H, ie, the breakdown electric field V / H of the material. There is a maximum value for the distance corresponding to the thickness H of the dielectric thin film 2 so as not to exceed. If the dielectric thin film 2 exhibits large variations in thickness over the entire area 3, the variation in electric field and thickness will be at the same level for a given voltage between conductive layers. As a result, a portion of the dielectric thin film 2 having a higher local electric field will stretch than one having a smaller local electric field. Furthermore, in the situation of a converter where the composite 1 operates near the breakdown electric field, this type of variation can damage the converter. This is because a part of the dielectric thin film 2 is exposed to an electric field exceeding the breakdown electric field. Therefore, it is very important to reduce the variation of the average thickness to the maximum possible range when processing the dielectric thin film 2. For processing reasons, an average thickness variation of 10% is considered acceptable. By design, i.e. when producing a transducer with corrugated electrodes according to the invention, these values can be controlled in a relatively accurate manner.

  FIGS. 3a and 3b show an electric field responsive composite 1 consisting of two conductive layers 4 separated by a dielectric thin film 2 exposed to zero potential difference (FIG. 3a) and exposed to high potential difference (FIG. 3b). As shown in FIG. 3b, when the dielectric thin film 2 is extended while being exposed to a potential difference, the conductive layer 4 is made uniform. This is illustrated in detail in FIGS. 4a to 4c, which show part of the cross section of the electric field response complex 1 at different stages over time, taking into account clarity and omitting the shading. A symmetry line 10 is shown at the bottom of each figure where the composite 1 is an electric field responsive composite having a conductive layer 4 deposited on each side. FIG. 4 a shows the electric field response complex 1 exposed to a zero potential difference, the waveform depth is the design depth d, and the waveform period is the design period P. FIG. 4b illustrates that the dielectric thin film 2 extends in the flexible direction, resulting in a thin film having a reduced thickness H '. Further, the conductive layer 4 is uniformed to provide a smaller waveform depth d 'and a larger waveform period P'. FIG. 4c shows the electric field response composite 1 at a time-lapse stage, in which the thickness H ″ of the thin film 2 is further reduced, the waveform depth d ″ is further reduced, and the waveform period P ″ is It is bigger.

  Note that capacitors produced in accordance with the present invention exhibit a “self-healing” mechanism. The self-healing mechanism is a characteristic of a capacitor with an ultrathin electrode. This is done when the dielectric material comprising the capacitor has defects such as inclusions and pinholes. For this type of capacitor with a given thickness, the average electric field approaches a dangerous breakdown electric field when the applied potential difference between the electrodes approaches the so-called breakdown voltage defined above. However, in areas with defects, this dangerous breakdown electric field is exceeded and a cascade effect occurs due to accelerated impact charges on the thickness of the dielectric thin film at the defect location, thereby causing large inrush transients on the dielectric material. A current is induced. This causes local transient overheating with microsecond range or characteristic time well below. It is sufficient to “reduce / disappear” the defects and the very thin counter electrode material in their immediate vicinity. This creates a region surrounding the defect where no more electrode material exists. Furthermore, the size of the region with reduced electrode material increases with the local electric field. However, this type of capacitor does not break and operates continuously. Thus, it is called “self-healing”. As long as the reduced area represents a negligible part of the total area of the capacitor as a whole, this will have a negligible impact on the performance of the capacitor. Self-healing does not occur when the capacitor is made of thick electrodes because the local overheating level is not sufficient to reduce the thick electrode material at the defect site. In that case, if the fatal destruction occurs, the capacitor is inevitably damaged instantaneously. In fact, the inventors of the present invention have made metal electrodes with a thickness up to 0.2 μm and have always observed self-healing even when the capacitor is operated in a faulty state. This will not cause any substantial damage to the capacitor and the capacitor will therefore continue to operate.

  FIGS. 5 to 9 show examples of the waveform of the composite 1 thereby creating a multilayer composite. As shown in FIGS. 5 a and 6 a, the electric field responsive multilayer composites 15, 16 each have a dielectric thin film 2 having a front surface 20 and a back surface 21, and at least two composites with the back surface 21 facing the front surface 20. A body 1 is provided. The front surface 20 includes a surface pattern 3 including a raised portion and a recessed portion, and a first conductive layer (not shown) that covers at least a part of the surface portion 3. FIGS. 5a and 6a show only a portion of the multilayer composite 15, 16, which has a different dimension of balance for illustration purposes.

  5a and 5b show an electric field responsive multilayer composite having a first composite 1 with its front face 20 facing a back face 21 of an adjacent composite 1, generally referred to below as a front-back multi-layer composite 15. The body 15 is shown. In this seed lamination step, the conductive layer of the first composite 1 is in direct contact with the back surface of the second composite 1. The composite 1 is laminated by either using the same type of elastomer that is used to produce the dielectric thin film 2 or by laminating the two composites 1 without using an adhesive. For some purposes, it is preferable to make a multilayer composite with a laminated composite that does not use an adhesive. In these cases, the wave valleys are simply filled with air.

  Because of the pattern 3 consisting of the raised surface portion and the recessed surface portion, the conductive layer of each composite can be made uniform as the thin film extends, and the thin film follows the direction defined by the arrow 5 (see FIG. 5b). When shrinking, it restores its original shape without causing damage to the conductive layer, and this direction thereby determines the flexible direction. That is, the multilayer composite 15 shown in FIG. 5b is designed to have flexibility in the direction of arrow 5 and designed to have rigidity in the direction of arrow 6.

  Figures 5c and 5d show the electric field responsive multilayer composite 15 exposed to zero potential difference and high potential difference. As can be seen from FIG. 5d, the dielectric layer is elongated while the conductive layer becomes uniform when exposed to a potential difference. Furthermore, it can be seen that the depth of the wave valley (wave depth d) is reduced when the multilayer composite is exposed to a potential difference. The composites can be bonded by applying a high potential difference to the laminated composite, whereby the thin film of one composite and the conductive layer of an adjacent composite can be brought into close contact with each other without the use of additional adhesive. Thus, they can be brought into close contact with the electrostatic force. Otherwise, due to the properties of the dielectric thin film which becomes slightly sticky when made of elastomers, they can be brought into close contact with each other, for example by pressing them against each other by the use of rollers.

  As an alternative so far, FIGS. 6a and 6b show a first composite with its rear face 21 disposed opposite the back face 21 of an adjacent composite 1 generally referred to below as a back-back multi-layer composite 16. An electric field responsive multilayer composite 16 having 1 is shown. The composite 1 can also be tightly bonded by the use of an elastomer adhesive having similar properties to the dielectric thin film 2 of the composite 1. Otherwise, the two composites 1 are laminated without using an adhesive.

  In the electric field responsive multilayer composite 16 shown in FIG. 6 a, the corrugated surface 3 can be covered with a conductive layer before or after corrugating the composite 1. The back-back multilayer composite 16 has the advantage that the effects of defects in the dielectric thin film 2, pinholes in the conductive layer, etc. can be made less dangerous when the adjacent layers do not have similar wrinkles in the immediate vicinity.

  If the individual composites 1 are made in the same production process, there will be an increased risk that the same folds are present at the same location of each composite 1. In order to reduce the effect of this seeding, it may be advantageous to shift the position of one complex 1 relative to the adjacent complex 1 or to rotate the complex 1 relative to each other.

  Lamination processing represents an indispensable process in the manufacturing process. Thus, a precise corrugating machine with tension control should be used.

  Similar to the multilayer composite 15, the composite 15 and the composite 16 shown in FIG. 6 b are designed with flexibility in the direction of the arrow 5 and designed with rigidity in the transverse direction of the arrow 6. is there.

  Figures 6c and 6d show the electric field responsive multilayer composite 16 exposed to zero potential difference and exposed to high potential difference. As can be seen from FIG. 6d, when exposed to a potential difference, the dielectric thin film extends while the conductive layer becomes uniform.

  FIG. 7a shows that an electric field responsive multilayer composite 15 of the kind shown in FIG. 5a can further accommodate an unlimited number of composites 1 according to specific requirements. The multilayer composite of FIG. 5a includes one dielectric thin film 2 of two dielectric thin films 2 that does not operate, i.e. only one of the two dielectric thin films 2 is placed between two conductive layers (not shown). It is. FIG. 7a shows that multiple composites reduce the effect of non-working layers on such an electric field responsive multilayer composite 15 because everything except the lowest composite 15 is located between the electrodes. Because.

  FIG. 7 b shows an alternative method of forming an electric field responsive multilayer structure 15 comprising an unlimited number of composites 1. The composite 1 is laminated by an adhesive layer 22 disposed between the composites 1 in such a manner that the composites 1 do not directly contact each other. The material of the adhesive layer 22 has properties similar to that of the dielectric material of the composite 1 in terms of stretch ability. This is to allow the adhesive layer 22 to stretch with the dielectric material when the multilayer structure 15 is activated. Thus, the adhesive layer 22 can conveniently be made from an elastomer, i.e., a material having elastomer-like properties.

  In FIG. 8, two similar electric field responsive multilayer composites 16, also shown in FIG. 6a, ie, back-back composites, are stacked on top of each other. In this electric field responsive multilayer composite, the conductive layers form a pair in contact with each other. Two dielectric thin films 2 are arranged between two of this set of two conductive layers. This laminate provides a reduced effect of manufacturing defects in the individual layers. In addition, a third or even one (or more) electric field responsive multilayer composite 16 can be added to the multilayer composite.

  FIG. 9 shows a stack of multilayer composites 16 similar to the stack shown in FIG. However, in the state shown in FIG. 9, the back-back multilayer composite 16 is laminated in pairs, and the multilayer composite 16 laminated in pairs is laminated together there. In the laminated body shown in FIG. 9, it is ensured that the conductive layers made of a pair of adjacent laminated bodies facing each other have the same polarity. Thus, this type of laminate can be wound without the risk of shorting the electrodes, and therefore the laminate is suitable for winding, for example in forming a tubular transducer.

  FIG. 10a shows the front-back electric field responsive multilayer composite 15 shown in FIG. Since the composite 1 can be manufactured with a very long length, so-called “endless” composite, the multilayer composite 15 is manufactured with a very long length, thereby forming a wound multilayer composite comprising a number of wound bodies. Can be made possible.

  FIG. 10 b shows the winding of the multilayer composite 15 around the rod 23. The rod 23 is disposed at the end of the multilayer composite 15, and the composite 15 is then wound around the rod 23 as shown. Thereby, the multilayer composite 15 has a wound tube shape.

  Figures 11a and 11b show a portion of a composite 24 suitable for forming a wound or otherwise stacked transducer. The composite 24 comprises a thin film 2 made of a dielectric material having a surface with a pattern consisting of a raised surface portion and a recessed surface portion, thereby forming a surface with a corrugated contour, ie, the thin film 2 is shown in FIG. It is similar to the thin film 2 of the composite. In this case, the thin film 2 includes a conductive layer having negative electrode portions 25 and positive electrode portions 26 arranged in an alternating pattern, that is, the negative electrode portions 25 and the positive electrode portions 26 alternately appear in the gaps therebetween. Within the air gap, no conductive layer is deposited on the dielectric thin film. Arrow 27 indicates that the composite 24 can be the very long “endless” composite shown in FIG. 13a or the folded composite shown in FIG. 13b.

  12a-12c show one possible method of making the composite 24 of FIG. FIG. 12 a shows film 2, which is a very long film on two rolls 30. A conductive layer (not shown) is deposited on the thin film 2 using a non-continuous evaporation roll method. An arrow 31 indicates the processing direction. The conductive layer is deposited via a shadow mask 32 so as to provide a gap between the electrode portions 25 and 26. When the conductive layer is deposited on a region of the thin film 2, the thin film 2 is wound in the direction of the arrow 31 and stops. A shutter (not shown) is opened and a conductive layer is deposited in an adjacent region of the thin film 2, which is adjacent to the previous region and provides continuous transient contact between electrodes of the same polarity. Guarantee. The shutter closes when the required thickness of the conductive layer is achieved. The electrode deposition principle that the electrodes are deposited through a shadow mask is more suitable for the production of electrodes having a certain width and gap for practical reasons. As an alternative, the air gap can also be created by laser ablation. In fact, it is preferable to create gaps by laser ablation because using this kind of technique it is very easy to have a variable distance between each gap and thus the variable width of each part of the conductive layer. It is. This will be explained in more detail below.

  FIG. 13a shows the composite 24a of FIGS. 11a and 12a, 12b formed as a wound composite 35. FIG. D and R represent the diameter and radius of the roll 36 around which the composite 24 is wound. The solid line represents the positive electrode, while the dotted line represents the negative electrode. Note that for clarity, the wound composite is illustrated by concentric circles. However, it should be understood that in practice the wound composite forms a helical pattern. The width w of the electrodes 25 and 26 and the width of the gap between these electrode portions are determined based on the cross-sectional area of the roll 36 as described below. That is, 2π (R) = w + gap, where the gap is very small compared to w. Furthermore, it is preferable that the thickness t of the composite 24a is smaller than the gap. Otherwise, the efficiency of the transducer formed by this winding will be small. When a wound body is created by rolling the composite 24a, the voids are shifted in a tangential direction with respect to the previous wound body at a thin film thickness level of 2πt · n. Thus, if the gap shift exceeds the gap width, electrodes with the same polarity tend to overlap, which renders the corresponding part of the capacitor inactive. The method builds an actuator with a limited number of turns and operates in a flat tubular actuator that deposits a pre-strained structure, ie, an electrode portion and a gap, on a portion of the dielectric web corresponding to the flat portion of the flat tubular actuator. It is suitable for making it. An alternative approach when using laser ablation to design electrodes with variable width but constant gap width would be more appropriate for rolled tubular actuators. In this case, the width of the gap and the reduced area is determined by moving the laser spot size, and the given electrode width associated with a given winding at the actuator growth perimeter is the width and gap at the winding circumference. Try to match.

  Similarly, FIG. 13 b shows the composite 24 b of FIG. 11 b as a folded composite 37. It is clear from FIG. 13b that the composite 24b is carefully folded so as to ensure that the opposite polarity electrodes 25, 26 are not in direct contact.

  FIGS. 14 a and 14 b show a laminate of the composite shown in FIG. 11 by folding the composite 24. Otherwise, the complex can be the seed shown in FIGS. 1a and 2. The composites 1 and 24 are manufactured in a long structure, whereby the lengths and widths of the composites 1 and 24 are determined, and a surface 3 having a pattern composed of a raised surface portion and a recessed surface portion is provided. This pattern forms wave peaks and valleys extending in a common direction, and the common direction is arranged substantially along the width of the long structure. Therefore, the composites 1 and 24 have flexibility in a direction perpendicular to the common direction, that is, along the length of the long structure.

  The composites 1 and 24 of FIG. 14 a are laminated such that the width of the resulting electric field responsive multilayer composite 40 is the same as the width of the composite 1 by folding the long structure along the length. Because of the orientation of the composites 1 and 24 in the flexible direction, the electric field responsive multilayer composite 40 will have flexibility in the direction indicated by the arrow 41.

  FIG. 14 b shows a laminate of composites 1, 24 according to another embodiment of the present invention. This is very similar to the embodiment shown in FIG. 14a. However, in this case the common direction is arranged substantially along the length of the elongate structure and the composites 1, 24 are therefore flexible in the direction along the width of the elongate structure as the composite of FIG. Therefore, the obtained electric field response laminated body 42 bends in the direction indicated by the arrow 43.

  Thus, the laminated composite shown in FIG. 14a bends along the length of the laminated composite. This means that the structure of FIG. 14a can be of any length, ie any desired stroke length. Similarly, the laminated composite of FIG. 14b bends along the width of the laminated composite. This means that the structure of FIG. 14b can be created with an arbitrary width. Thus, it is possible to design a transducer with any suitable dimensions according to the geometric requirements of the intended application.

  15a-15c are perspective views of a direct actuating transducer 50 according to one embodiment of the present invention. The linear motion transducer 50 of FIGS. 15a-15c is manufactured by winding a multilayer composite, such as the seed shown in FIG. 1a or FIG. The transducer 50a of FIG. 15a is solid, whereas the transducer 50b of FIG. 15b is hollow. The transducer 50 can have any elongated shape, for example, a substantially cylindrical or elliptical shape or a substantially cylindrical shape with a curved cross-section formed as shown in FIG. 15c.

  In FIGS. 15 a-15 c, the composite wound to form the columnar transducer 50 has a flexible direction parallel to the direction indicated by arrow 51. Thus, when electrical energy is applied to the electrodes of linear motion transducer 50, transducer 50 extends axially in the direction of arrow 51. When the transducers 50 are properly made and dimensioned according to certain aspects of the present invention, they can exert a considerable force on axial loads that tend to resist axial extension.

  As previously indicated herein, the electric field responsive composites of the present invention are extremely flexible and easy to bend, similar to ordinary household adhesive films and polyethylene shopping bag sheet materials in their ease of bending. As explained above, composites are extensible in one direction and differ from these materials due to their higher elasticity, which is very poor in extensibility in the vertical direction, as well as their mechanical anisotropy.

  The inventor understands that a roll formed by winding up a sufficiently long composite would be very rigid, regardless of the flexibility, flexibility and elasticity of the composite. ing. If the roll is wound properly for the mechanical anisotropy of the thin film, it will have the axial flexibility that mechanical anisotropy introduces, and it still resists bending under axial loading. be able to.

  Therefore, the composite of the wavy anisotropic dielectric thin film layer having the conductive electrode layer is wound into a tubular shape with a sufficient number of turns to make the tubular element generation structure sufficiently robust to prevent bending. Can do. In this context, the term “bending” means a state in which the elongate structure deforms by bending due to an applied axial load. It has been found that any additional components, such as any stiffening rods or springs within the elongate structure, do not need to obtain sufficient stiffness to eliminate bending under the technically useful level of axial loading. Yes. The required rigidity can be obtained simply by winding up a sufficient number of wound bodies made of a composite material.

  The winding structure shown in FIGS. 15a-15c is designed to withstand a specific maximum load level with a load sufficient to eliminate bending. This specific maximum level can be, for example, a predetermined level of force with a predetermined level of extension, or it can be the maximum level of driving force, shut-off force or transducer with a shorter length in the direction of arrow 51. It is also possible to achieve a higher force level that occurs when compressed into

  The design parameters for the linear motion transducer described in this application are optimized according to the design criteria developed by the inventors. These design criteria make it possible to determine the optimum dimensions of a wound actuator (transducer) based on actuator performance specifications.

  The mechanical and electrostatic properties of the electric field response composite are used as a basis for estimating the drive actuator force and stroke per unit area. The winding actuator described in accordance with the present invention is made by winding / spooling the ultra-thin electric field response composite shown in FIGS. 1a and 1b, for example, having a thickness in the 1 μm range. A typical actuator of this kind can be made up of thousands of windings and can include as many as 100 turns per mm of actuator wall thickness.

  When driven, linear / push actuators convert electrical energy into mechanical energy. A portion of this energy is stored in the form of potential energy of the actuator material and can be reused for use when the actuator is discharged. The remaining part of the mechanical energy is effectively available for driving. Full conversion of this remaining portion of mechanical energy to drive energy is only possible if the actuator structure does not become mechanically unstable due to axial compression as in known defect bending modes. . This can be achieved by appropriately dimensioning the cross-sectional area of the actuator in relation to the actuator length. Mathematically, this corresponds to Euler's column stability theorem. According to the present invention, this theorem also applies to columnar actuators formed by winding up a sufficient number of turns of the electric field responsive multilayer composite.

  The optimization process begins by defining the level of force required for a given application. Next, based on the driving force per unit area, it is possible to estimate the cross-sectional area required to reach that level of force.

For cylindrical structures, the critical axial load or force Fc for a given ratio between the length and radius of the cylinder is
Fc = c · π ² · E · A / (L / R) ²
Given by. here,
c is a boundary condition dependent constant,
E is the elastic modulus,
A is the cross-sectional area of the cylindrical body,
L is the length of the cylindrical body,
R is the radius of the cylindrical body.

Now consider a cylindrical electric field responsive polymer converter driven by applying a voltage V to the electrode. In an unloaded condition, the transducer is simply elongated. When the axial load is suppressed, the transducer will exert a force on the load that increases with the voltage V. The maximum force F _max that can drive the transducer depends on the configuration of the transducer.

For a given length L and cross-section A, this means that the voltage needs to be controlled in a way that does not allow forces greater than F _max <F _c . For a given cross section, this means that the length of the cylinder must be less than the critical length L _c , ie L <L _c , where L _c is defined as:

For a transducer 50 having a given cross-sectional area and a selected maximum force level, the maximum force level associated with the maximum voltage level, ie the limit length Lc, is given by the formula L _c ≤ {c · r ² · π ² · E / (F _max / A)} ^1/2
The design rule is L <L _c .

At a selected voltage level, the converter 50 having the required cross section can be driven with a given maximum force, the so-called 0% extension breaking force F _bl . In this situation, the design code is
L _c = {c · r ² · π ² · E / (F _bl / A)} ^1/2
It becomes.

To apply these design criteria for a transducer 50 made of an elastomer having E = 1 MPa, F _bl / A = 20 N / cm ² , c = 2, the design criteria for F _max = F _bl is L _bl = 10 · r, that is, the so-called slender ratio λ, must satisfy the following condition in order to obtain a non-bent structure at a load equal to the breaking force.
λ ≦ L / r = 10

At a lower level with respect to the driving force for the same transducer 50, i.e. alternatively selected for a cylindrical symmetric transducer 50 having the same radius r, the design rule for the length L is the following equation: L ≦ L _bl · ( F _bl / F) ^1/2
Can be derived from

For example, if the drive level of 10% extension is (1/4) · F _bl , then the length L of the converter at 10% extension is
L ≦ L _bl · {1 / (1/4)} ^1/2 = L _bl · 2
Means that

  Euler's theorem can be applied to the design of selected percentage stretches of transducer 50 and dielectric film with specific needs for transducer stroke. Because of the increased number of turns, there is no restriction on the increase in the cross-sectional area A of the cylindrical symmetrical transducers 50a and 50b, and the design criteria derived from Euler's theorem are realized. Thus, it is possible to determine the number of turns necessary to obtain a required level of driving force. Therefore, it is possible to construct a dielectric transducer having non-bending properties at a given force level and a given stroke for linear motion by the techniques described above.

When designing a direct acting capacitive transducer, it is necessary to dimension its mechanical structure against bending. This is usually accomplished by increasing its cross-sectional second moment, known as I. As an example, a piece of paper having a given thickness (h), width (w), and length (L) bends when a slight force is applied to the paper in a direction parallel to the length. become. However, by winding it in the width direction, a very large force will be required to bend it. The winding-flat flexural rigidity ratio is then given by (3/2) · {1+ [w / (h / π)] ² }. An example of this type is w = 40 mm and h = 1 mm, where the ratio is about 245.

Stabilization of the actuator against any mechanical instability requires that the cross section be dimensioned by increasing the cross section secondary moment I. A low value of I results in a less stable structure and a high value of I results in a very stable structure against bending. Design parameters for dimensioning the structure is the turning radius r _g and a cross-sectional moment I about the cross-sectional area A. R _g Low values of result in more stable poorly actuator, r _g of high value results in very stable actuator. After having defined optimum ranges for both area A and radius of gyration r _g, it is possible to determine the optimum range for the rolled actuator wall thickness about r _g in the form of t / r _g. The thickness t of the area A and radius r _g and the wall is a design parameter for dimensioning the actuator cross-section toward the maximum stability. T / r _g of low values result in very stable actuator structures, t / r _g of high value results in a more stable without the actuator structure.

Once the range of cross-sectional parameters is determined, it is necessary to estimate the maximum length of the actuator that does not cause bending due to axial compression for the required level of force. Slenderness defined as the ratio of the length L to the radius of the turning radius r _g are generally used parameter in relation with Euler's theory. Low value of L / r _g result in very stable actuator structures, the L / r _g high values result in less stable actuator structures against bending.

  Once all the design parameters for the optimal active linear actuator have been determined, the actuator is constructed based on the actuator wall thickness t and the number of turns n per mm for a given electric field response complex with a specific thickness in the μm range It is possible to estimate the total number of turns required to do this.

In a preferred embodiment, the ratio n / t between the number of turns n of the transducer and the wall thickness t should be in the range of 10 turns / mm to 50 turns / mm. Furthermore, slenderness ratio is the ratio between the turning radius r _g of the transducer and the length L of the transducer should be less than 20. The turning radius r _g is r _g = (I / A) ^{1/2 where} I is the sectional area moment and A is the sectional area of the transducer.

  Thus, careful design of the transducer in accordance with the present invention makes it possible to obtain a large driving force even if very soft dielectric materials are used. The driving force can even reach levels comparable to conventional transducers made from harder materials, such as magnetic transducers. This is a great advantage.

FIG. 16a is a graph showing force as a function of stroke in a linear motion transducer in accordance with one embodiment of the present invention. When a voltage is applied to the anisotropic flexible conductive layer of the transducer, the field induced compression across the entire film thickness is converted into an extension / stroke along the transducer's flexible direction. The compressive strain is called Maxwell strain P, and the corresponding driving force is called electrostatic force F _{electrostatic} . When stretched, the dielectric material exerts an opposing force F _elastomer that increases with the transducer stroke as shown in FIG. 16a.

As a result, the effective force Fact that can be used for linear motion is derived from the two described forces, and F _act = F _{electrostatic} −F _elastomer as shown in FIG. 16b. A characteristic curve representing the force vs. stroke of a linear actuator is common for force transducers, where the driving force decreases as a function of increasing stroke, and finally the maximum value of the stroke is “as shown in FIG. The one corresponding to "zero" driving force is reached.

FIG. 16c shows the range of calculated linear power as a function of transducer stroke for different outer diameters of a linear capacitive transducer, ie a wound transducer. Large driving forces in the range of hundreds to thousands of newtons can be generated. The breaking force is usually four orders of magnitude greater than the nominal driving force defined by the 10% transducer stroke. A direct acting capacitive transducer made of a dielectric material having a thickness of 40 μm with an elastic modulus in the range of 0.5-1 MPa is 0.1-0.2 N / per unit area for a typical drive voltage of 3000 volts. A force in the range of mm ² will be generated. When considering the cross section of the large transducer, this corresponds to the large driving force shown in FIG. 16c.

  17a and 17b are perspective views of a linear motion transducer 52 according to an alternative embodiment of the present invention. The transducer 52 of FIGS. 17a and 17b has a deflection direction along the tangent of the cylindrical body. Accordingly, the extension of the transducer 52 occurs at the periphery of the tubular structure indicated by the arrow 53, i.e., the transducer 52 is caused to expand and contract in the radial direction.

  FIG. 18 a shows a stack of composites 1 forming a flat tubular structure 60. The complex 1 can conveniently be the seed shown in FIGS. 1a and 2. The transducer 60 consists of a stack of sufficiently tightly bonded composites to ensure the stiffness of the transducer, which stiffness is sufficient to allow the transducer to operate without pre-straining. The transducer 60 is manufactured, for example, by winding a continuous composite of the kind shown in FIGS. 1a and 2 in a very flat tubular structure. By using this design, the constraints on the number of layers described above are removed. Thereby, the transducer 60 can be made as powerful as necessary, as described above with reference to FIGS. 15a-15c.

  The flat tubular transducer 60 shown in FIG. 18 a is obtained by rolling the composite 1 around two spaced rods 61 to form a winding pattern of the composite 1. Due to the orientation of the composite 1 in the flexible direction, the flat tubular structure 60 will be flexible in the direction indicated by the arrow 62. FIG. 18 b shows the converter of FIG. 18 a pre-strained by two springs 63.

  19a to 19c are perspective views of the transducer 70 having a flat structure. Transducer 70 is a multi-layer composite composed of enough tightly bonded composites to ensure the rigidity of the transducer, which is sufficient to allow the transducer to operate as an actuator without pre-straining. It is as. The transducer 70 is manufactured, for example, by laminating a continuous composite of the type shown in FIGS. 1a and 2 in a flat structure. By using this design, the constraints on the predetermined number of layers described above are removed. Thereby, the transducer 70 can be made as powerful as required, similar to that described above with reference to FIGS. 15a-15c. Transducer 70a is a multi-layer composite composed of a sufficiently large number of tightly coupled composites to guarantee the stiffness of the transducer, which stiffness is sufficient to ensure that the transducer can operate as an actuator without pre-straining. The converter 70b has a predetermined size by stacking several converters 70a. As an alternative to this, the transducer 70c can be pre-strained by a spring 71 or by other elastically deformable elements.

  The converters 70a and 70b are provided with a fixed flange 72 in order to mount the converter in the application, for example to operate the converter as an actuator. An arrow 73 indicates a bending direction.

  20a to 20e show the transducer 80 in operation with a preload applied. FIG. 20 a is a perspective view of a flat transducer 80 provided with a fixing flange 81. The flat transducer 80 in FIG. 20 a is pre-strained by a spring 82. Accordingly, the flat transducer 80 has the drive direction indicated by arrow 83. FIG. 20 b shows a similar flat transducer 80 in which the spring is replaced by a similar second flat transducer 80. FIG. 20c shows half of the transducer, which is similar to the transducer of FIG. 20b and is sized by using a predetermined number of identical transducers (only half of which are shown). FIGS. 20d and 20e show two alternative transducers 84 and 85, each with a fixed number of flat transducers 80 that are predistorted by adjacent transducers similar to the transducer of FIG. 18b. The transducers 84 and 85 are driven in the cross direction in FIG. 20d in the carpet-like structure and FIG. 20e in the wall-like structure.

  Note that the transducers of FIGS. 18-20 only require pre-strain in one direction, the flexible direction. Thus, pre-straining in the direction transverse to the flex direction is necessary for prior art transducers, but not for transducers according to the present invention.

  FIG. 21 shows two pre-strained transducers 90 having a flat tubular structure, which actuate in the longitudinal direction and thereby rotate the drive shaft 91.

  FIG. 21b shows two mechanical pre-strained flat transducers 92, 93 with a mechanical connection 94 supported by a guide element for sliding purposes. The converters 92 and 93 are shown in three states. In the first state, both transducers 92 and 93 are not operating. However, they are both mechanically prestrained. In the second state, the converter 93 is operating. Because the transducer 92 is in an inactive state, the transducer 93 relaxes the transducer 92, thereby releasing some of the mechanical predistortion of the transducer 92. In the third state, the converter 92 is operating, but the converter 93 is not operating. The transducer 92 thereby relaxes the transducer 93, thereby releasing some of the mechanical pre-strain of the transducer 93. Thus, transducers 92 and 93 combine with mechanical connector 94 to form a dual active transducer, where one of the transducers relaxes the other transducer and releases mechanical predistortion.

  FIG. 22 shows an electric field responsive composite comprising a dielectric thin film 2 comprising a first surface 100 and a second surface 101 opposite to the first surface 100. The both sides of the dielectric thin film 2 are partially covered with a conductive layer. Due to the shape and position of the conductive layer, there is an actuating portion A, where the electrode portions 102 and 103 of the conductive layer cover both surfaces 100 and 101 of the dielectric thin film 2. The conductive layer further includes a first passive portion B in which only the second surface 101 of the dielectric thin film 2 is covered with the contact portion 104 of one conductive layer, and only the first surface 100 of the power source dielectric thin film 2 is covered with the other. And the second passive portion C covered with the contact portion 105 of the conductive layer. As its appearance, the electric field responsive complex can be electrically connected to a power source, or can be connected to a control means that controls the driving of the complex by coupling conductors 104,105. Even if the illustrated composite is stacked, wound, or folded to form a transducer having a large number of layers, the electrode portions 102 and 103 are, for example, conductive wires on the layers in the contact portions 104 and 105. It can be easily connected to the power source by penetrating the rod and rod and connecting the wire and rod to the power source. The ratio between the thickness of the dielectric thin film 2 and the thickness of the conductive layer is for illustration purposes only. The processing method shown in FIG. 22 can be referred to as “offset”, which means that the contact portions 104, This is because 105 is disposed.

  FIGS. 23a-23c show three different ways of spatially shifting two composites 1 of a multilayer composite forming a transducer, where each composite 1 comprises a conductive layer on a dielectric thin film. The illustrated composite 1 has a flexible direction that extends or contracts when the transducer is driven. In FIG. 23a, the contact portion is a space shifted along the flexible direction of FIG. 23b, the contact portion is shifted perpendicular to the flexible direction, and in FIG. The space is shifted in both directions perpendicular to the direction. In any structure, it is desirable to maintain a region in which physical contact is made between the multilayer composite and some source of strain, i.e., connecting wires, rods or similar conductors that are spaced from the movable part. FIG. 23d shows the multilayer composite viewed from the side.

  Thus, FIGS. 22 and 23a-23c illustrate two different principles of disposing the contacts 104, 105: the “offset” principle of FIG. 22 and the “spatial shift” principle of FIGS. 23a-23c. These principles can be combined with various lamination methods and the appropriate principle can be selected accordingly for the intended application.

  FIG. 24 shows that the contact portions 104 and 105 form a part of the conductive layer, and an extended isolated portion is formed on one side of the electrode portions 102 and 103. The isolated portions of two adjacent composites in the multi-layer composite are arranged differently so that the contact portions 104, 105 of the adjacent composites are spaced from each other.

  FIG. 25 shows two composites each comprising a conductive layer. When the composites are combined into a multilayer composite, they are offset from each other, thereby forming a contact portion 104 in which a portion of the conductive layer on each composite is spaced from the corresponding contact portion 105 on the other composite.

  FIGS. 26 and 27 similarly show the tubular transducer 50 shown in FIGS. 15a and 15b. The tubular transducer is connected to the power source at the indicated contact points 104, 105.

  FIG. 28 shows a transducer 110 having a flat tubular structure. The converter includes contact portions 104 and 105 on the inner surface. The contact portion can be connected to a power source through one of the elongated rods 111 having a conductive contact portion, for example. The rod 111 is shown in an enlarged view of FIG. 29, in which the rod 111 is provided with two contact portions 112, 113, which are contact points of the tubular structure when the rod 111 is inserted into the tubular structure. The parts 104 and 105 come into contact with each other. The rod 111 can also form part of the device in which the transducer operates. Both the spatial shift principle and the offset electrode principle can be applied to contact with the transducer structure described above.

  FIG. 30 shows three different connectors: a soft connector 120, a metal-coated plastic connector 121, and a metal or metal-coated grip strip connector 122. FIG. The soft connector 120 includes an elastomeric thin film 123 that is coated with a layer of conductive material 124. Similarly, the metal-coated plastic connector 121 includes a plastic portion 125 that covers a metal layer 126.

  31-35 show the composite 1 with electrical contacts. Since the composite 1 of the present invention is very soft, it is difficult to combine the composite 1 with a slightly more rigid ordinary electrical connector such as a wire, strip or lattice.

  FIG. 31 shows a soft connector 120 connected to a composite 1 comprising a dielectric thin film 2 having a corrugated surface 3 comprising a layer of conductive material 4. The soft connector 120 and the conductive portions 124 and 4 of the composite 1 are joined together via a layer of conductive adhesive 127, whereby the composite 1 and the soft connector 120 are electrically connected.

  FIG. 32 shows two composites 1 combined as described above, ie, through a layer of conductive adhesive 127, and the composite 1 placed on top is used as the main electrode for the power source.

  FIG. 33 shows a metal or metal-coated wire or strip 128 connected to the composite 1. The metal or metal coated wire or strip 128 is connected to the main power source. As described above, the metal, the metal-coated wire, or the strip 128 is combined with the conductive layer 4 of the composite 1 by the conductive adhesive 127. In this case, however, the conductive adhesive 127 surrounds the periphery of the metal or metal-coated wire or strip 128, and thus between the metal or metal-coated wire or strip 128 and the wire layer 4 of the composite 1. Are arranged in such a way as to provide extremely efficient electrical contacts.

  FIG. 34 shows a metal or metal coated grip strip connector 122 connected to the composite 1 via a conductive adhesive 127. As described above with reference to FIG. 33, the conductive adhesive 127 is arranged so that a portion of the metal or metal-coated grip strip connector 122 is completely enclosed thereby providing a very good electrical contact. is there.

  FIG. 35 shows a metal-coated plastic connector 121 connected to the composite 1 via a layer of conductive adhesive 127. As described above with reference to FIGS. 31 and 32, the layer of conductive adhesive 127 is disposed between the metal layer 126 of the metal-coated plastic connector 121 and the conductive layer 4 of the composite 1, and thereby between the two. Provide electrical contacts.

  FIG. 36a shows a manufacturing process of a tool or a mold for manufacturing a composite, for example, composite 1 shown in FIG. FIG. 36b shows a manufacturing method for producing a composite by using a tool, and FIG. 36c shows a manufacturing method for producing a transducer from the composite.

  Thus, the manufacturing method starts by creating a parent mold having a desired waveform contour. This mold can be made by laser interference lithography on photoresist coated glass or standard lithography on silicon wafers.

  For standard lithography on silicon wafers, the exposure mask is relatively simple, and preferably presents equidistant parallel lines having, for example, a width of 5 μm and a spacing of 5 μm. Using standard silicon microfabrication techniques, the silicon is etched to form a so-called V-groove structure, ie, a groove having a cross-sectional shape similar to “V”. A series of oxidation and hydrofluoric acid etching steps are then performed to transform the V-groove structure into a pseudo sine wave waveform when it is in the desired shape.

  Here, a parent mold having a relatively large size of 32 cm × 32 cm or the like at maximum can be formed by laser interference lithography. In laser interference lithography, two laser beams, each having an enlarged spot size and a uniform energy distribution across the beam cross section, are interfered onto a photoresist-coated glass substrate. This kind of process does not require any exposure mask and relies on interference phenomena known in the optical field. The result of exposure, development and last hard-bake is a direct curved waveform contour written on the photoresist, where the contour period and amplitude are the laser beam wavelength and the angle of incidence of the laser beam on the photoresist. It depends on the thickness of the photoresist.

  In the next step shown in FIG. 36, a standard undistorted electroplating process is used to produce a sufficient number of nickel replicas or molds necessary to obtain a corrugated microstructure replica on a plastic roll. create. These nickel replicas, called wedges, have a thickness in the range of 100 μm. These wedges are mechanically attached in a series of structures to form a “belt” having a length that is precisely set to match the periphery of the embossing drum. The use of thin wedges facilitates their bending without undue strain and facilitates subsequent “belt” winding around the drum periphery. Each wedge is positioned relative to its neighbor and the waveform is adjusted with μm accuracy to minimize angular misalignment between adjacent wedge lines. The corrugated microstructure of the embossing drum obtained from the nickel mold is then accurately replicated on a plastic roll. This can be done by fine embossing between rolls (ultraviolet light or heat curing). Embossing between rolls enables the production of rolls of finely embossed plastic material having a length in the range of several hundred meters. Finely embossed plastic rolls are used in the form of carrier webs, for example belts or molds for the production of dielectric thin films with single or double corrugations, for example elastomeric thin films having a length in the range of several hundred meters.

  A corrugated elastomer thin film or sheet of a limited size is produced by known spin coating. It is a discontinuous process and the maximum dimension of the thin film or sheet is determined by the size of the mold. An alternative type of manufacturing process is a species developed for the polymer industry, such as adhesive tape and coating, commonly referred to as “roll-to-roll coating” or “web coating”. These manufacturing processes are large in size and large capacity, and are continuous processes.

  In a subsequent step, an elastomeric thin film is produced using a fine embossing roll, for example using a reverse roll to roll, gravure, slot die, or any other suitable type of coating technique. As a result, an elastomer-coated plastic thin film is obtained. To this end, reverse roll and gravure roll coating techniques are considered the most promising of other known techniques because they provide a uniform coating and have a relatively good thickness Because. The surface characteristics of the embossing resin are selected in such a way that it can be humidified by an embossed plastic roll or mold and an elastomeric material. In order to manufacture a high-quality elastomer thin film without a pinhole, an elastomer thin film manufacturing process is performed in a clean room environment.

  The uncured elastomeric film formed on the mold described above is exposed to heat, ultraviolet light, or any other source that can initiate crosslinking to cure the elastomeric film. The source selected will depend on the type of elastomeric material used, particularly the curing mechanism of the material used.

  Next, the cured thin film is removed from the molded body by a layer peeling method. For this purpose, an appropriate release finish is used. Preferably, the molding material and the elastomer material are selected to facilitate the removal process. A very fragile adhesion of the cured elastomer to the substrate module is preferred. If good adhesion occurs, the release process may fail and damage the film. Single side corrugated elastomer thin film rolls are products of this delamination process.

  In the next step, a metal electrode is deposited on the corrugated surface of the elastomer thin film by vacuum web metal film formation. Therefore, a metal coating, such as silver, nickel or gold, is deposited on the corrugated surface. Thus, a complex is formed.

  The challenge in mass production of elastomeric thin films with lengths in the range of kilometers is not in the production of flat thin films, but rather on one or both sides with a precise and very well formed microstructure. In the production of corrugations. Another challenge lies in handling very soft materials with a controlled tension that is a fraction of a magnitude larger than the control tension that normally occurs in the polymer industry. When the thickness of the coating layer is only 1 / 100th of the depth of the corrugated pattern, the manufacturing method of the metal coating of the corrugated elastomer thin film with the reliable coating layer becomes another challenge.

  Next, the coated elastomer thin film, ie, composite, is laminated, thereby forming a multilayer composite as described above. The multilayer composite is then wound to form the final winding transducer structure. The wound transducer applies electrical connection after finishing and cutting.

  Finally, the completed transducer can be integrated into the final product along with the control electronics, thus allowing the transducer to be used immediately.

It is a figure which shows the continuous roll of the spool suspension composite_body | complex which becomes embodiment of this invention. It is a figure which shows the continuous roll of the spool suspension composite_body | complex which becomes embodiment of this invention. It is a one part perspective view of the composite_body | complex which becomes one Embodiment of this invention. It is a partial sectional view of the composite_body | complex which becomes embodiment of this invention. It is a partial sectional view of the composite_body | complex which becomes embodiment of this invention. It is a partial sectional view of the composite_body | complex which becomes embodiment of this invention. It is a partial sectional view of the composite_body | complex which becomes embodiment of this invention. It is a partial sectional view of the composite_body | complex which becomes embodiment of this invention. It is a partial sectional view of the composite_body | complex which becomes embodiment of this invention. FIG. 2 is an enlarged view of FIGS. 2a, 2b, 2c, 2d, 2e, and 2f. Figures 3a and 3b show an electric field response complex exposed to a zero potential difference and an electric field response complex exposed to a high potential difference. 4a to 4c are diagrams showing the effect of exposing the electric field response complex of FIG. 3a to the high potential difference shown in FIG. 3b. It is a figure which shows an example of the waveform of the composite_body | complex which becomes one Embodiment of this invention which forms an electric field response multilayer composite. It is a figure which shows an example of the waveform of the composite_body | complex which becomes one Embodiment of this invention which forms an electric field response multilayer composite. FIG. 3 shows an electric field responsive multilayer composite exposed to zero potential difference and exposed to high potential difference. FIG. 3 shows an electric field responsive multilayer composite exposed to zero potential difference and exposed to high potential difference. It is a figure which shows another example of the laminated body of the composite_body | complex which becomes one Embodiment of this invention which forms an electric field response multilayer composite. It is a figure which shows another example of the laminated body of the composite_body | complex which becomes one Embodiment of this invention which forms an electric field response multilayer composite. FIG. 5 shows an electric field responsive multilayer composite exposed to zero potential difference and high potential difference. FIG. 5 shows an electric field responsive multilayer composite exposed to zero potential difference and high potential difference. It is a figure which shows an example of the waveform principle of the composite_body | complex which becomes embodiment of this invention. It is a figure which shows an example of the waveform principle of the composite_body | complex which becomes embodiment of this invention. It is a figure which shows an example of the waveform principle of the composite_body | complex which becomes embodiment of this invention. 10a and 10b show examples of wound electric field response complexes. FIG. 11a is a diagram showing an example of a part of a composite according to an embodiment of the present invention, and the composite is particularly suitable for a composite having a wound structure, and FIG. 11b shows an embodiment of the present invention. It is a figure which shows an example of a part of composite which becomes, and a composite is especially suitable for the composite_body | complex which has a folding structure. It is a figure which shows the preparation method of the composite_body | complex of FIG. 11, and a part of tool required for the manufacture. FIG. 13a shows the composite of FIG. 11a formed as a wound composite, and FIG. 13b shows the composite of FIG. 11b formed as a folded composite. 14a and 14b are diagrams showing the waveform of the composite shown in FIG. 11 by folding the composite. 15a to 15c are perspective views of an axial linear motion transducer according to an embodiment of the present invention. It is a graph which shows the force as a function of the stroke in the linear motion converter which becomes one Embodiment of this invention. It is a graph which shows the force as a function of the stroke in the linear motion converter which becomes one Embodiment of this invention. It is a graph which shows the force as a function of the stroke in the linear motion converter which becomes one Embodiment of this invention. 17a to 17b are perspective views of a radial linear motion transducer according to an embodiment of the present invention. FIG. 18a shows the corrugation of the composite forming the flat tubular structure, and FIG. 18b shows the flat tube structure of FIG. 18a with pre-strain. 19a to 19c are perspective views of a drive transducer having a flat structure. It is a figure which shows the drive converter which gave the preload. It is a figure which shows the drive converter which gave the preload. It is a figure which shows the drive converter which gave the preload. It is a figure which shows the drive converter which gave the preload. It is a figure which shows the drive converter which gave the preload. FIGS. 21 a and 21 b show two drive transducers having a flat tube structure and a drive transducer having a mechanical connection. It is a figure which shows the principle of the space shift waveform layer of a composite_body | complex. It is a figure which shows a waveform electric field response multilayer composite provided with an electrical contact part and an electrical connector. It is a figure which shows an example of an electric field response multilayer composite provided with an electrical contact part. It is a figure which shows an example of an electric field response multilayer composite provided with an electrical contact part. It is a figure which shows an example of the converter provided with an electrical contact part. It is a figure which shows an example of the converter provided with an electrical contact part. It is a figure which shows an example of the converter provided with an electrical contact part. It is a figure which shows an example of the converter provided with an electrical contact part. It is a figure which shows a different electrical connector. It is a figure which shows an electric field response composite body provided with a contact electrode. It is a figure which shows an electric field response composite body provided with a contact electrode. It is a figure which shows an electric field response composite body provided with a contact electrode. It is a figure which shows an electric field response composite body provided with a contact electrode. It is a figure which shows an electric field response composite body provided with a contact electrode. It is process drawing explaining the manufacturing process of the converter which becomes one Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Electric field response composite, 2 Thin film, 3 Upper surface, 4 Conductive layer, 10 Symmetry line, 15, 16, 40 Electric field response multilayer composite, 20 Front surface, 21 Back surface, 22 Adhesive layer, 23 Rod, 24, 24a, 24b , 35, 37 composite, 25 negative electrode part, 26 positive electrode part

Claims (46)

A multilayer composite comprising a plurality of composites,
Each complex is
A thin film made of a dielectric material, having a front surface and a back surface, the front surface comprising a surface pattern comprising a raised surface portion and a recessed surface portion;
A first conductive layer having a corrugated shape deposited on the surface pattern and formed by the surface pattern of the thin film ;
The dielectric material is a polymer;
The multi-layer composite, wherein the front surface of the back-rear multi-composite in which the back surfaces of the respective composites are opposed to each other faces the front surface of another back-back multi- layer composite. The multilayer composite according to claim 1 , wherein the composites are adhesively bonded together. The multilayer composite according to claim 2 , wherein the composite is adhesively bonded using an adhesive having a hardness approximately equal to the hardness of each composite. The multilayer composite according to any one of claims 1 to 3 , wherein a surface pattern of the thin film of each composite is substantially the same. The surface pattern of the thin film of each composite comprises waves forming peaks and valleys extending in a common direction, the flexibility of the conductive layer in which the waves deform in a direction perpendicular to the common direction, and thereby the multilayer composite The multilayer composite according to any one of claims 1 to 4 , which determines the anisotropic characteristics of the body. The multilayer composite according to claim 5 , wherein the wave has a periodically repeating shape. The multilayer composite according to claim 5 or 6 , wherein the wave has one or both of a shape and a dimension that change periodically along a direction perpendicular to the common direction. The multilayer composite according to any one of claims 5 to 7 , wherein each wave specifies a shortest distance between a mountain and an adjacent valley, and a maximum wave has a height of at most 110% of an average peak value. . The multilayer composite according to any one of claims 5 to 8 , wherein each wave specifies a shortest distance between a mountain and an adjacent valley, and the minimum wave has a height of at least 90% of an average peak value. The multilayer composite according to any one of claims 5 to 9 , wherein the thin film has an average thickness of 10 to 200 µm. 11. A composite according to any one of claims 5 to 10 , wherein the ratio between the average peak value of the wave and the average thickness of the thin film is between 1/50 and 1/2. The composite according to any one of claims 5 to 11 , wherein an average peak value of the wave is between 1/3 µm and 20 µm. The wave according to claim 5 to 12 , wherein the wave has a wavelength specified as the shortest distance between two peaks, and the ratio between the average peak value and the average wavelength of the wave is between 1/30 and 2. The complex according to any one of the above. 14. A composite according to any one of claims 5 to 13 , wherein the ratio between the average thickness of the first conductive layer and the average height of the waves is between 1/1000 and 1/50. A composite according to any one of claims 1 to 14 wherein the first conductive layer has a thickness of 0.01 to 0.1 [mu] m. The multilayer composite according to any one of claims 1 to 15, further comprising a composite longer in the longitudinal direction than in the vertical transverse direction. The multilayer composite according to claim 16 , wherein the surface pattern forms wave peaks and valleys extending in a substantially longitudinal direction. The multilayer composite according to claim 16 , wherein the surface pattern forms wave peaks and valleys extending in a substantially transverse direction. The multilayer composite according to any one of claims 1 to 18 , wherein the surface pattern comprises a plurality of identical sub-patterns. 20. A multi-layer composite according to any one of claims 5 to 19 , wherein the composites are arranged together and have the shortest possible distance between one layer crest and the other layer crest. 21. A multi-layer composite according to any one of claims 5 to 20 , wherein the composites are arranged one above the other and have the longest possible distance between one layer crest and the other layer crest. The multilayer composite according to any one of claims 5 to 21 , wherein the multilayer composite is prestrained in a direction perpendicular to the direction of the peaks and valleys. The multilayer composite according to claim 22 , wherein the multilayer composite is stretched by an elastic deformation structure. 24. The multilayer composite according to any one of claims 1 to 23 , wherein the multilayer composite is arranged in connection with an electrical control means for converting between electrical energy and mechanical energy. 25. The multilayer composite of claim 24 , wherein the multilayer composite is disposed against an object and applies pressure to the object using electrostatic forces. The multilayer composite according to any one of claims 1 to 25 , wherein the multilayer composite comprises a spherical edge coated with an electrically insulating layer. 27. The multilayer composite according to any one of claims 1 to 26 , wherein the thin film is made of silicon elastomer or acrylic elastomer or a combination thereof. 28. The multilayer composite according to any one of claims 1 to 27 , wherein the thin film of the composite is an adhesive that directly bonds onto an adjacent composite. The multilayer composite according to any one of claims 1 to 28 , wherein the first conductive layer is a metal. 30. The multilayer composite of claim 29 , wherein the metal is selected from the group consisting of silver, gold, and nickel. The two composites form part of a single continuous thin film made of a dielectric material having a surface pattern composed of a raised surface portion and a recessed surface portion on the front surface, and the first conductive layer is formed of the surface pattern. Deposited on a first portion, a second conductive layer is deposited on a second portion of the surface pattern, and the first and second conductive layers are electrically insulated from each other; 31. The multilayer composite according to any one of claims 1 to 30 , wherein the thin film is formed by folding or winding an insulating first and second conductive layer in a multilayer structure in which the first and second conductive layers are alternately arranged between the layers of the thin film. . The composite thin film forms a dielectric layer having a first surface and a second surface facing the conductive layer, and the conductive layer comprises:
In the active part of the actuator, the active part in which the electrode part of the conductive layer covers both surfaces of the dielectric layer;
A first passive portion and a second passive portion, wherein only one surface of the dielectric layer is covered with one of the conductive layers;
The first passive portion is formed by the contact portions of the conductive layer of the first surface, the claims 1 to 31 the second passive portion is formed by the contact portion of the conductive layer of the second surface The multilayer composite according to any one of the above. The multilayer composite according to claim 32 , further comprising an electrical connector attached to each contact portion, wherein the electrical connector extends beyond an edge portion of the multilayer composite to facilitate connection of the conductive layer to a power source. The multilayer composite according to any one of claims 1 to 33 , wherein each composite has a shape that is not substantially affected by contact between the thin film and the conductive layer. The multilayer composite according to any one of claims 1 to 34 , wherein the resistance of the dielectric material exceeds 10 ¹⁰ Ω · cm. The multilayer composite according to any one of claims 1 to 35 , wherein the resistance of the conductive material is less than 10 ^-4 Ω · cm. 37. A multilayer composite according to any one of claims 1 to 36 , wherein the resistance of the dielectric material is greater than ¹⁰ < ¹⁰ > [Omega] .cm for each composite. The multilayer composite according to any one of claims 1 to 37 , wherein the resistance of the conductive material is less than 10 ^-4 Ω · cm for each composite. A method of forming a multilayer composite comprising a dielectric thin film and a conductive layer,
Providing the first composite comprising a thin film comprising a dielectric material having a back surface opposite the front surface, wherein the front surface comprises a surface pattern comprising a raised surface portion and a recessed surface portion;
Depositing a conductive layer on the surface pattern;
Providing the second composite comprising a thin film comprising a dielectric material having a back surface opposite the front surface, wherein the front surface comprises a surface pattern comprising a raised surface portion and a recessed surface portion;
Depositing a conductive layer covering at least a portion of the surface pattern;
Disposing the first composite on the second composite so that the back surfaces face each other ;
Fixing the position of the first complex relative to the second complex;
Disposing the front surface of the back-back multiple composite composed of the first composite and the second composite so as to face the front of another back-back multilayer composite;
Only including,
The method wherein the dielectric material is a polymer . 40. The method of claim 39 , wherein the location is secured using an adhesive disposed between the composites. 41. The method of claim 40 , wherein the position is fixed using a fixing means located at an edge portion of the composite. The method according to any one of claims 39 to 41 , wherein the composites are mutually arranged in a step of moving the composites forward in a processing direction while being biased toward each other. Each thin film of the composite is provided with a shape specifying element having a surface pattern composed of a raised surface portion and a recessed surface portion, and a liquid polymer composition is disposed on the surface pattern to raise the raised surface portion and the recessed surface portion. 43. A method according to any one of claims 39 to 42 , wherein the method is provided by forming a first thin film having a surface with a replication pattern comprising: The thin films of the respective composites are provided using the same shape specifying elements or using the same shape specifying elements, and the composites are displaced from each other to displace the wrinkles of the thin film caused by the shape specifying elements from each other. Item 44. The method according to Item 43 . 45. The method of claim 43 or 44 , further comprising depositing a first conductive layer on the replicated surface pattern. A transducer comprising the multilayer composite according to any one of claims 1 to 38 .

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